| // Ceres Solver - A fast non-linear least squares minimizer |
| // Copyright 2015 Google Inc. All rights reserved. |
| // http://ceres-solver.org/ |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // * Redistributions of source code must retain the above copyright notice, |
| // this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above copyright notice, |
| // this list of conditions and the following disclaimer in the documentation |
| // and/or other materials provided with the distribution. |
| // * Neither the name of Google Inc. nor the names of its contributors may be |
| // used to endorse or promote products derived from this software without |
| // specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| // POSSIBILITY OF SUCH DAMAGE. |
| // |
| // Author: Sameer Agarwal (sameeragarwal@google.com) |
| |
| #include "ceres/single_linkage_clustering.h" |
| |
| #include <unordered_map> |
| |
| #include "ceres/graph.h" |
| #include "gtest/gtest.h" |
| |
| namespace ceres { |
| namespace internal { |
| |
| TEST(SingleLinkageClustering, GraphHasTwoComponents) { |
| WeightedGraph<int> graph; |
| const int kNumVertices = 6; |
| for (int i = 0; i < kNumVertices; ++i) { |
| graph.AddVertex(i); |
| } |
| // Graph structure: |
| // |
| // 0-1-2-3 4-5 |
| graph.AddEdge(0, 1, 1.0); |
| graph.AddEdge(1, 2, 1.0); |
| graph.AddEdge(2, 3, 1.0); |
| graph.AddEdge(4, 5, 1.0); |
| |
| SingleLinkageClusteringOptions options; |
| std::unordered_map<int, int> membership; |
| ComputeSingleLinkageClustering(options, graph, &membership); |
| EXPECT_EQ(membership.size(), kNumVertices); |
| |
| EXPECT_EQ(membership[1], membership[0]); |
| EXPECT_EQ(membership[2], membership[0]); |
| EXPECT_EQ(membership[3], membership[0]); |
| EXPECT_NE(membership[4], membership[0]); |
| EXPECT_NE(membership[5], membership[0]); |
| EXPECT_EQ(membership[4], membership[5]); |
| } |
| |
| TEST(SingleLinkageClustering, ComponentWithWeakLink) { |
| WeightedGraph<int> graph; |
| const int kNumVertices = 6; |
| for (int i = 0; i < kNumVertices; ++i) { |
| graph.AddVertex(i); |
| } |
| // Graph structure: |
| // |
| // 0-1-2-3 4-5 |
| graph.AddEdge(0, 1, 1.0); |
| graph.AddEdge(1, 2, 1.0); |
| graph.AddEdge(2, 3, 1.0); |
| |
| // This component should break up into two. |
| graph.AddEdge(4, 5, 0.5); |
| |
| SingleLinkageClusteringOptions options; |
| std::unordered_map<int, int> membership; |
| ComputeSingleLinkageClustering(options, graph, &membership); |
| EXPECT_EQ(membership.size(), kNumVertices); |
| |
| EXPECT_EQ(membership[1], membership[0]); |
| EXPECT_EQ(membership[2], membership[0]); |
| EXPECT_EQ(membership[3], membership[0]); |
| EXPECT_NE(membership[4], membership[0]); |
| EXPECT_NE(membership[5], membership[0]); |
| EXPECT_NE(membership[4], membership[5]); |
| } |
| |
| TEST(SingleLinkageClustering, ComponentWithWeakLinkAndStrongLink) { |
| WeightedGraph<int> graph; |
| const int kNumVertices = 6; |
| for (int i = 0; i < kNumVertices; ++i) { |
| graph.AddVertex(i); |
| } |
| // Graph structure: |
| // |
| // 0-1-2-3 4-5 |
| graph.AddEdge(0, 1, 1.0); |
| graph.AddEdge(1, 2, 1.0); |
| graph.AddEdge(2, 3, 0.5); // Weak link |
| graph.AddEdge(0, 3, 1.0); |
| |
| // This component should break up into two. |
| graph.AddEdge(4, 5, 1.0); |
| |
| SingleLinkageClusteringOptions options; |
| std::unordered_map<int, int> membership; |
| ComputeSingleLinkageClustering(options, graph, &membership); |
| EXPECT_EQ(membership.size(), kNumVertices); |
| |
| EXPECT_EQ(membership[1], membership[0]); |
| EXPECT_EQ(membership[2], membership[0]); |
| EXPECT_EQ(membership[3], membership[0]); |
| EXPECT_EQ(membership[4], membership[5]); |
| } |
| |
| } // namespace internal |
| } // namespace ceres |